Project Proposal – What Makes a Wetland?

Defined as first- and second-order streams, headwaters and their adjacent wetlands establish the beginning of a river network. Located at the interface between uplands and surface water networks, headwater wetlands intercept shallow ground water and surface runoff, acting as a natural filter to improve downstream water quality. Important ecosystem functions provided by headwater wetlands include sediment retention, flood attenuation, and the removal of pollutants/excess nutrients. Headwaters also contribute to regional biodiversity by providing habitat/refuge, and sustain downstream aquatic and riparian biota by exporting essential products such as food, nutrients, and woody debris.  As compared to higher order streams, the loss or degradation of headwater wetlands is expected to have a disproportionate impact on downstream water quality.

Hydrology is the single most important factor driving the structure and function of wetlands, including headwater systems. Changes in hydrologic cycles resulting from land use and climate change have contributed to the degradation of streams, wetlands, and other aquatic ecosystems throughout the nation. The consequences of altered hydrology have been studied extensively in many aquatic ecosystems, however it is unclear to what extent land use and climate change will affect the hydrologic regime of headwater wetlands, particularly in flat coastal landscapes such as the coastal plain of Virginia.

Despite no net loss policies and specific guidance for mitigation of wetland impacts, Virginia continue to lose wetlands and ecosystem service capacity through both permitted activities and natural processes. My dissertation research seeks to inform the conservation and management of Virginia’s headwater wetlands by 1) identifying which wetlands are most vulnerable to climate change in the coastal plain of Virginia and 2) describing how the character and condition (i.e., land use) of headwater catchments influence their vulnerability to climate change stressors.

While direct wetland impacts such as filing and draining are immediately obvious, the indirect hydrologic impacts due to land use and climate change that I study require some understanding of wetland hydrology. An important concept fundamental to my research is the movement of water to and from headwater wetlands. One component of this work involves modeling water table fluctuations that contribute to the formation of wetlands in the coastal plain. The soil saturation conditions required to establish and maintain a wetland are consistent between all wetland types – the main differences being how the water is transported to and from the wetland. Therefore I would like to develop a product that teaches the fundamentals of wetland hydrology, in other words, what makes a wetland a wetland?

I plan to create a short (2-3 minute) whiteboard animation describing the hydrology of wetlands that could be used as an educational tool in schools and for the general public. I expect this product would be most appropriate for middle and high school aged students, and would complement lessons on the water cycle and/or wetlands. However, since it would not require in depth understanding of the water cycle, it could also be used in outreach events such as VIMS Marine Science Day. In addition to describing basic wetland hydrology, this video would focus on illustrating the hydrologic connectivity of wetlands to watersheds and downstream ecosystems. Other topics that I may cover include describing how hydrology influences the capacity of wetlands to perform ecosystem functions, and demonstrating how temperature and precipitation alter watershed/wetland hydrology.

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